At 41, McCauley is no stranger to victory, having won the national club title twice previously, as well as the national road race five times and the national time trial three times.
McCauley also coaches other athletes, many of whom were racing at the weekend.
''I knew I was going good before the race. I had a win in Auckland and then another win in Otago, so it was just a case of how much the week would take out of me,'' he said.
McCauley got into the breakaway with under-23 rider Matt Zenovich (Southland) and second-placed Alex McGregor (Otago), dropping Zenovich in the last few kilometres and outsprinting McGregor in the final straight.
McCauley is now preparing for the Tour of Adelaide, where he will race with the Australian-based Drapac team.
The outstanding performance of the day went to Zenovich, who won the under-23 men's race after attacking in the first kilometre over the demanding and hilly course.
Zenovich (19), who is riding his first season in the under-23 category, made his move from the start and spent the entire race either out on his own or in the breakaway.
Richard Lawson (Southland) crossed the line 59sec behind Zenovich to claim second in the under-23 race.
Jim McMurray made a solo break during the first lap of the men's masters four race, and crossed the line in impressive fashion, 3min ahead of Brent Marryatt (Pegasus) and Dave Lawson (Papanui).
On Saturday, outstanding young cyclist Sophie Williamson embraced the tricky conditions to win the elite women's title.
Blustery winds, rain and cold temperatures made for a tough day on the bike, as riders battled for national titles.
Williamson, the gun Alexandra rider representing the Central Otago-Wakatipu club, claimed the elite women's title in convincing fashion.
She made a decisive breakaway with Ashleigh Neave (Ramblers) just after the halfway mark in the race, then cleared out to take a solo victory by more than a minute.
Willliamson said the conditions added to the suffering on an already challenging course.
''It was just freezing. I can't feel my toes,'' Williamson said.
''It was a tough day for everyone. I don't think you can get used to this weather. It's not much fun to ride in at all. All you can do is give it a nudge and get it over and done with as fast as possible.''
Williamson said she did not feel at her best on the start line, but was pleased with how the race unfolded.
''My plan was always to attack and make it a hard race and see what happens. I didn't know that that attack was going to make it but we just kept it steady and it turned out it did.
''You never know how your legs are going to go during the race, so you just see what you can do.''
The under-19 women's race finished in a tight sprint between Devon Hiley and Robin Hacker-Carey. Hiley edged her way to the win.
Stratford's Mel Titter out-sprinted Cameron Alexander (Timaru) and Stu Crooks (Otago) to win the men's masters two race.
On Friday, Otago's Ross Gamble claimed an impressive win in the men's masters seven race, and Southland's Josh Haggerty won the under-19 men's title.
